Cementing plug and valve device for well casings



Feb- 3, 1953 R. c. BAKER ET AL 2,527,314

CEMENTING PLUG AND VALVE DEVICE FOR wELL CASINGS Filed Nov. 14, 1949 TVJK .vv u u @WEEE A?. E E fi@ m wwf MMM /QTTOEWEYIS Patented Feb. 3, 1953CEMENTING PLUG AND VALVE DEVICE FOR WELL CASINGS Reuben C. Baker,Coalinga, and Benjamin Lewis Austin, Long Beach, Calif., assignors toBaker Oil Tools, Inc., Vernon, Calif., a corporation of CaliforniaApplication November le, Nilis, Serial No. 127,189

(Ci. 16S- i) 10 Claims. 1

The present invention relates to subsurface well devices, and moreparticularly to combination plug and valve devices adapted for downwardmovement through well conduits, such as casing strings, in theperformance of several desirable functions therein.

This application is a continuation-in-part of our application forPositive Shut-Off Ported Casing Apparatus, Serial No. 22,886, iiledApril `23, 1948.

An object of the present invention is to provide improved cementingplugs especially useful at the upper end of a charge of cementitiousmaterial, and capable oi eiiectively closing a passage in a well boreupon engaging a companion valve seat.

Another object of the invention is to provide a cementing plug that isslidable along the wall of a casing string, and capable of cooperatingwith a sleeve valve to effect its hydraulic shifting from port closingposition without interfering with the passage of fluids through theports.

A further object of the invention is to provide a lcernenting plugadapted to slidably seal with the wall of a well casing, and alsocapable of being squeezed into a cooperable valve seat t0 obtainpositive sealing with the seat and to insure that the plug will notinterfere with fluid passage through a side port in the well casingabove the seat.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of severalforms in which it may be embodied. Such forms are shown in the drawingsaccompanying and forming part of the present specification. These formswill now be described in detail, illustrating the general principles ofthe invention; but it is to be understood that such detailed descriptionis not to be taken in a limiting sense, since the scope of the inventionis best deiined by the appended claims.

Referring to the drawings:

Figure l is a longitudinal section through a ported well apparatus, withthe ports open, after having been closed, and with a top cementing plugand valve device descending towards a cooperable valve seat;

Fig. 2 is a view similar to Fig. 1, with the ports reclosed and with thetop cementing plug and valve device squeezed into an upper sleeve valve;

Fig. 3 is a combined longitudinal section and side elevation through amodiiied form .of cementing plug and valve device.

As disclosed in the drawings, a casing collar A has its upper and lowerends threadedly confi O ` the tubular member groove 23. u

2 nected to the ends of upper and lower casing sections B, C formingpart of a casing string ladapted to be run in a well bore to positionthe collar at 'the desired location therein.

`The collar A includes -a tubular member I0 whose lower end Consists ofa coupling I I th'r'eaded onto the upper end of the lower casing sectionC. A stop member I2 is ysecured to the exterior of the coupling, as bythe use of welding material I3, to serve a purpose described below.

The tubular member I0 lhas a plurality of circularly spaced side portsI`4 through which fluids are adapted to pass between the interior andexterior of the collar apparatus. These Aports are closed initially by alower inner sleeve valve member I5 having seal rings I6, II disposed inlsuitable ring grooves I8 on opposite sides of the ports. These rings maybe of rubber and of round cross-section 'to prevent leakage thereby inboth longitudinal directions. y

The lower inner sleeve valve member I5 is re tained in position tolocate its seal rings I6, Il on opposite sides of the ports I4 by one ormore frangible devices in theform of shear screws I9 threaded throughthe tubular member IIJ and extending into the valve member.

It is to be noted that the inside diameterof the tubular member I0,atthe region where it is engaged by the lower seal ring I1, is less thanthe internal diameter of 'a groove '23 in the inember I0 immediatelybelow this region. Also, the sleeve valve member I5 is reduced in'external diameter to form `a peripheral groove 24 below the lower sealring I'I, in which a split, inherently expansible stop ring 25 islocated. The stop ring has an upper inner inclined surface 26 Vtaperingdownwardly and inwardly for cooperation with a corresponding taperedsurface 2l on the base of the peripheral groove 24. The length of thegroove 24 is much greater than the length of the stop ring to permitdownward movement of the sleeve valve member I5 relative to the stopring. u

The ring 25 is received within the enlarged diameter portion 23 of thetubular member., ,Ifhis enlarged portion is much longer than. the heightof the stop ring. The stop ring may rest upon a shoulder 28 provided Aby the lower end', of `the peripheral groove 24, theupper end ofthe-stop ring being engageable with an upper lshoiilder!) of theperipheral groove 24. Downward' movement of the stop ring is limited byits engagement with the shoulder `BEI iorr'nedl by the lower end oi Theshear screws I9 are adapted'to be dise 3 rupted and the lower innersleeve valve member I5 moved downwardly to a position in which the upperseal ring I5 is disposed below the ports I4. The ports are then open tothe passage of uid between the interior and exterior of the apparatus(Fig. l).

After the ports have been opened, it is desired to reclose them. Toaccomplish this purpose, an external sleeve valve member 3| is providedon the tubular member I0. This external member has a plurality oflongitudinally spaced seal rings 32, 33 disposed in internal grooves 34and slidably engageable with the outer surface of the tubular member I5.The outer member 3| has an upwardly extending cylinder 35 integraltherewith, or otherwise suitably secured thereto, which is slidablealong an enlarged portion Ida of. the tubular member.

The outer member 3| is retained initially in an upward position, inwhich it does not close the ports |4, by one or more shear screws 36threaded through the cylinder 35 into the enlarged portion ma of thetubular member. These screws are disruptable hydraulically by iluidpressure, including fluid under pressure entering through one or moreelongate ports, slots or openings 31 in the tubular member into acylinder space 38. This space is formed between the enlarged portion i3dof the tubular member, the cylinder skirt 35 and the part 3Ia of thesleeve valve member carrying the seal rings 32, 33. Leakage in adownward direction between the sleeve valve member 3| and Vtubularmember I0 is prevented by the seal ring 32. Leakage in an upwarddirection therebetween is prevented by a seal ring 33 disposed in aperipheral groove 45 in the enlarged portion lila of the-tubular member,which sealingly engages the inner surface of the cylinder 35.

When sufcient hydraulic force is exerted on the outer sleeve valvemember 3 I, the shear screws 33 will be disrupted and the outer sleevevalve member 3| shifted downwardly to a position in which its seal rings32, 33 are located on opposite sides of the ports I4, closing such portsagainst passage of fluids therethrough in both directions between theinterior and exterior of the apparatus. This position of the sleevevalve member 3| is determined by engagement of its depending skirt 4|with the upper end of the stop member |2. It is to be noted that theupper portion of the skirt 4| is spaced outwardly from the tubularmember |I| so as to avoid interfering with passage of fluids through theports I4 after they have been opened. This fluid flows through the portsI4 and through slots 4m in the lower end of the skirt. The end isslidable upon the member I0 and has a lower, knife-like edge 4|b capableof cutting through any materials that might coat the member I, or tendto prevent downward movement of the outer sleeve valve member 3|.

After the outer sleeve valve member 3| has 'been shifted downwardly toport closing position,

it is prevented from moving upwardly again by a latch or lock ring 42disposed Within a peripheral groove 43 in the tubular member I l) aboveits seal ring 39. This lock ring consists of a split, inherentlyexpansible member having a reduced diameter lower portion 42a forming ashoulder 44 `with the upper portion 42h. The shoulder is inclinedoutwardly in a downward direction to a slight extent.

' When the outer sleeve valve member 3| has been forceddownwardly toessentially its fullest extent, the upper end 35a of the cylinder isdisposed below the shoulder 44 of the split lock ring, but not below thelower end of its reduced diameter portion 42a. As a matter of fact, theupper part of the cylinder 35 will be in engagement with the outersurface of the reduced diameter portion 42a, the lock ring 42 inherentlyexpanding outwardly to a certain Aextent upon riding of the cylinder oiits upper portion 4212. Any tendency for the outer sleeve valve member Y3| to move upwardly will be limited by engageshear screws ment of theupper cylinder end 35a with the lock ring shoulder 44, the lock ringbeing forced against the upper end of the peripheral groove 43. Toinsure against inward forcing of the lock ring 42 from engagement withthe end 35a of the cylinder, the latter is tapered in the same directionas the shoulder 44, so that the two will remain in snug contact with oneanother.

The force of iluid under pressure is prevented from acting upon theexternal sleeve valve member 3| by an upper inner sleeve valve member 45having longitudinally spaced seal rings 45 disposed in ring grooves 41on opposite sides of the elongate ports or slots 31. This valve memberis held in position by one or more shear screws 48 threaded through thetubular member ||l into the upper valve member 45. Disruption of theshear screws 48 and downward shifting of the upper sleeve valve member45 will expose the ports 31 and permit fluid under pressure to passthrough the latter into the cylinder space 38, in order to assist inshearing the cylinder screws 35 and moving the outer sleeve valve member3| downwardly to port closing position.

The upper inner sleeve valve member 45 is not only used for the purposeof controlling the pas sage of uid through the elongate ports 31, but isalso used in assisting downward movement of the external sleeve valvemember 3| to port closing position.

To accomplish this latter purpose, the upper inner sleeve valve member45 and external sleeve Valve 3| have an intervening lost motionconnection. As specifically disclosed in the drawings, the outer sleevevalve 3| is formed with a plurality of inner keyways 36, in which arereceived the `lug or arm portions 3| of keys 82 secured to the upperinner sleeve member 45 and extending outwardly through the elongateports or slots 31. Each key includes a leg portion 83 depending from thearm portion 8| and adapted for movement within the tubular member i5with the upper inner valve member 45.

It is to be noted that the arm 8| of each key is disposed originallyabove the lower end or shoulder 84 of the keyway 80. This arrangement isprovided for the purpose of permitting the inner valve member 45 to movedownwardly to an extent sufficient to shift the upper seal ring 4S belowthe upper ends of the ports 31, and thereby allow fluid to pass into theannular cylinder space 38 for action upon the sleeve 3| to effectshiftf' ing, or at least assisting in shifting, the sleeve Valve 3|downwardly to port closing position. `As described in detail below, oncethe elongate ports 31 are open, iiuid under pressure may enter thecylinder space 38 through these ports, disrupt the shear screws 35 andshift the outer valve inem- `ber 3| downwardly to port closing position.Ir" this hydraulic force is insuflcient, then pressure may be imposedupon the entire crossnsectional area of the upper inner sleeve valve 45,which will be transmitted to the external sleeve valve 3| lthrough thekeys 62 and abutting shoulders 84.

Asv stated above, the lower sleeve valve member I5 is held initially inclosed position by its I9. Similarly, the upper sleeve atomare valvemember lis held in closed position over the `elongate ports 31 by shearscrew-s 48, preferably closely adjacent or in abutting relation with'the upper end of lthe lower valve member I5. The upper valve 45 has acentral bore VIll whose wall tapers downwardly and inwardly. Similarly,the lower valve member I5 has a downwardly and inwardly tapering centralbore 50, which, in effect, forms a continuation of the upper member bore49. The cylinder screws 36 hold the outer valve member 3| in its upperposition.

With both sets -o ports I4, 31 closed, a fluent material, such as cementslurry, may be pumped directly into the casing string and through thecentral bores or passages 43, 3e in both sleeve valve members 45, I5,for discharge from the well casing at some point below the collar, as,for

`example, from a casing shoe (not shown). This charge of cement slurrywill pass upwardly through the annulus around the casingstring and mayextend approximately to the location of the collar A, or slightlythereabove.

When it is desired to eject a second or upper charge of cement slurrythrough lthe collar ports I4, a trip device or plug `member 5I isdropped into the wellcasing and is allowed to gravitate through thefluid therein into engagement with the wall oi the central bore in thelower sleeve valve member I5.

Pressure may now be applied to the iluid in the casing above the tripmember El and sleeve I5 in an amount suiiicient to shear the screws I3and shift the lower sleeve valve member I5 downwardly to port openingposition, as shown in Fig. 1.

Downward movement of the lower valve member is limited by engagement ofthe stop ring 25 with ythe shoulder 30 of the tubular member Ill, and ofthe shoulder 23 on the lower sleeve member I5 with the stop ring.Washing fluid, followed by cement slurry or other cementitious material,may new be discharged outwardly through the open ports I4, passingthrough the annular space between the tubular member I0 and thedepending skirt 4I of the outer valve member 3 I, and through the slots4 i a in the lower end of this skirt, for upward movement through theannulus around the collar A and casing string.

Upon discharging the required quantity of cement slurry, the outersleeve valve 3| is forced downwardly to port closing position. IThis actmay be accomplished by placing a top cementing plug 58 at the upper endof the charge of cement slurry pumped outwardly through the ports I4.This plug will come to rest within the bore 43 of the upper sleeve valvemember 45, allowing the fluid inthe casing string above the collar A tobe pressurized to an. extent suihcient for shearing the screws 48, toshift the upper inner valve member 45 downwardly to a position in whichthe upper ends of the elongate ports 31 are open.

The top cementing plug 58 disclosed in the drawings is of a compositecharacter. It includes a lower nose 59, which may be made of magnesium.,aluminum or other suitable, readily drillable material, having a taperedperiphery 6D adapted to conform to the taper of the passage 43 in theupper sleeve 45. This nose is so proportioned as to seat within thepassage and cause the top oementingplug A58 to come to rest therewithin.From its tapered nose, the lower end of the plug is integral with acentral shank 6I terminating in a vflange 62, received within arcompanion bore 'and recess 33 of a flexible portion B5 of the cementingplug. aresuitably vulcanized together.

The llexible plug 65 is formed essentially of rubber or similarmaterial. It has an inwardly7 compressible body portion 'lil defined bytapered forward and rearward surfaces 1I, 12 merging into an annularperipheral sealing surface 13 slidably engageable with the wall of thewell casing. The plug 65 also has a tail portion 14 terminating in afluted guide 15. Its annular sealing portion includes an upwardlyextending lip 16 adapted to be forced outwardly by fluid pressureagainst the wall of the casing.

The tapered nose 53 on the lower plug portion has a greater diameterthan the minimum diameter through the upper sleeve valve 45. As aresult, it comes to rest within the tapered bore 49 fof the latter,closing it against passage of fluid and allowing pressure to be built upin the casing fluid above the cementing plug 58, sufiicient in extent toshear the screws t3 and shift the upper member de downwardly to aposition limited by `engagement of the key lugs 8l with the shoulders 34forming the lower end of the keyways 48l) in the outer sleeve 3l. Whenin this position, the upper ends of the elongate ports 31 are exposed,allowing fluid to pass into the cylinder space 33 for the purpose ofshearing the cylinder screws 33 and moving the outer sleeve 3Idownwardly yto port closing position (Fig. 2)

A standard top `cernenting plug would not permit uid to pass -by it andenter the ports 31. The flexible plug 35 described above, however, willhave its body 'lll and annular sealing portion 13 deformed inwardly to asufficient extent to compress the rubber material into the taperedpassage 49 through the upper inner valvemember 45, sealing 01T thispassage completely,I while removing the annular sealing portion 13 ofthe plug from engagement with the casing wall or inner wall of thetubular member Ill (see Fie'. 2). The plug, therefore, offers norestriction or barrier to passage of nuid through the ports -31, foraotion upon the outer sleeve valve member 3|.

The top cementing plug 58 serves its normal function of conning thecharge of cement slurry in advance of it, by slidably sealing with thewall of the well casing during its downward passage. It insures therelease of the upper valve member 45, to open the elongate ports 31,since it is squeezed to a substantial extent into the sleeve valvemember 43. Such squeezing action insures a tight seal with the sleevevalve 65, and also removes the peripheral sealing portion 13 cornpletelyfrom engagement with the casing wall, in view of the squeezing of thisperipheral portion into the sleeve valve. As a result, the peripheralsealing portion cannot interfere with the ability of fluid topass-through the elongate ports 31, for the purpose of hydraulicallyshifting the outer sleeve valve member 3l downwardly to a positionclosing the portsl Ifl.

squeezing of the peripheral portion 13 into the sleeve valve occurs as aresult of locating such peripheral portion substantially adjacent thenose or valve head 5S of the device. The leading face 'il of thefiexible cementing plug body 1% extends from the peripheral sealingportion 13 to the valve head 59, and cooperates with the tapered walliii in the sleeve valve i5 to `assist in bodily compressing theperipheral portion 1S within the sleeve valve 45.

A modif-led form of cementing plug and valve device is illustrated inFig. 3, in which a generally spherical nose or head 33a depends from aThese two par ts central shank Bla fitting within a companion centralbore 63a of the flexible cementing plug. The shank extends through thebody portion 19 of the lflexible plug and also through its tail portion14, the central shank terminating in an upper flange 62a disposedadjacent the fluted guide 15, which is integral with the tail portion.

As in the other form of invention, the flexible plug has a peripheralportion 13a for slidable sealing with the wall of the well casing, aswell as an upwardly extending peripheral lip 16a. In addition, theleading surface 1hr is present in the flexible body, converging from theperipheral portion 13a towards the generally spherical nose or head 59a.

To insure against any leakage between the valve head 59a and the taperedwall 49 of the sleeve valve 45, a spherical seal is provided over thesurface of the spherical valve head 59a. This spherical seal may be madeof rubber or rubber-like material, and is preferably integral with theflexible cementing plug portion of the device. The seal extends aroundthe head 59a and terminates in an upwardly directed annulus IDI fittingwithin an end groove m2 in the forward or lower portion of the valvehead 59a, for the purpose of securing the lower end of the seal firmlywithin the valve head.

In all respects, the device illustrated in Fig. 3 functions in the samemanner as the cementing plug and valve device shown in Figs. 1 and 2.The plug slidably seals with the wallof the well casing in maintainingthe cement slurry separate from the displacement fluid above the plug.Its head and seal 59a, |50 can ft within the valve sleeve 45 with theseal lill] insuring against leakage thereby. The peripheral portion 13acan also be squeezed into the tapered portion 69 of the sleeve valve 45,to insure that a leakprcof seal is present between the device and thesleeve Valve 45, and also to remove such portion 13a completely fromcontact with the casing wall. In this manner, fluid above the plugdevice can pass freely through the elongate ports 31 into the cylinderspace 38, to move the outer sleeve valve 3| downward through hydraulicaction.

The inventors claim:

l. A cementing plug, including a forward rigid valve head portion and atrailing inwardly compressible elastic body having a peripheral portionfor slidable sealing engagement with the wall of a well conduit, saidbody also having a leading portion adjacent said head portion which hasan outer surface converging from said peripheral portion to said headportion, the maximum diameter of said valve head portion beingmaterially less than the maximum diameter of said peripheral portion.

2. A cementing plug, including a forward rigid valve head portion and ashank extending'upwardly from said head portion, an inwardlycompressible elastic body receiving said shank, said body having aportion adjacent said head portion for slidable sealing engagement withthe wall of a well conduit, the maximumdiameter of said valve headportion being materially less thanthe maximum diameter of that portionof the body which slidably engages the wall of the well conduit.

3. A cementing plug, including a forward rigid valve head portion and ashank extendingupwardly from said head portion, said shank having aflange at its upper end, an inwardly compressible elastic body receivingsaid shank and flange, said body having a portion adjacent said headportion for slidable sealing engagement with the wall of a well conduit,the maximum diameter of said valve head portion being materially lessthan the maximum diameter of that portion of the body which slidablyengages the wall of the well conduit.

4. A cementing plug, including a forward rigid valve head portion, arigid shank integral with and extending upwardly from said head portion,an inwardly compressible elastic body receiving said shank, said bodyhaving a peripheral portion for slidable sealing engagement with thewall of a well conduit, said body also having a leading portion adjacentsaid head portion which has an outer surface converging from saidperipheral portion to said head portion, the maximum diameter of saidvalve head portion being materially less than the maximum diameter ofsaid peripheral portion.

5. A cementing plug, including a forward rigid valve head portion and aninwardly compressible elastic body having a portion adjacent said valvehead portion for slidable sealing engagement with the wall of a wellconduit, and an elastic seal integral with said body and disposed on theforward face of said head portion.

6. A cementing plug, including a forward rigid generally sphericallycurved valve head portion, an inwardly compressible elastic body havinga portion adjacent said valve head portion for slidable sealingengagement with the wall of a well conduit, and an elastic generallyspherically curved seal integral with said body and disposed over saidspherically curved head portion.

7. A cementing plug, including a forward rigid valve head portion and ashank extending upwardly from said head portion, an inwardlycompressible elasticl body receiving said shank, said body having aportion adjacent said head portion for slidable sealing engagement withthe wall of a well conduit, and an elastic seal disposed over said valvehead portion, said seal being integral with said body.

8. A cementing plug, including a generally conical forward rigid valvehead portion and a shank extending upwardly from said head portion, aninwardly compressible body receiving said shank, said body having aperipher-al portion adjacent said head portion for slidable sealingengagement with the wall of a well conduit, said body also having aleading portion which has an outer surface converging from saidperipheral portion to said head portion.

9. A cementing plug: including a forward generally spherically curvedrigid valve head portion; a rigid shank integral with and extendingupwardly from said head portion; an inwardly compressible elastic bodyreceiving said shank, said body including a trailing portion disposedaround said shank, a peripheral portion adjacent said head portion forslidable sealing engagementwith the wall of a well conduit, and aleading portion having an outer surface converging from said peripheralportion to said head portion.

' 1i). A cementing plug: including a forward generally sphericallycurved rigid valve head portion; a rigidl shank integral'with andextending upwardly from said head portion; an inwardly vcompressibleelastic body receiving said shank, -A-said body including a trailingportion disposed around said shank, a peripheral portion adjacent saidhead portion for slidable sealing engagement with the wall of a wellconduit, anda leading por- .tion having an outer surface Vconvergingfromsaid peripheral portion to said head portion; and

9 a spherically curved seal on said sphercally curved valve headportion, said seal being integral with said body.

REUBEN C. BAKER. BENJAMIN LEWIS AUSTIN.

REFERENCES CITED The following references are of record in the le ofthis patent:

Number 10 UNITED STATES PATENTS Name Date Wickersham July 28, 1931Manning May 23. 1933 Morrisett Aug. 15, 1939 Baker Apr. 9, 1940 BrownOct. 7, 1941 Baker Mar. 6, 1945 Baker et al Jan. 3, 1950

